Quantum Leap in Understanding Grape Vine Nutrition


In the August 2021 edition of Growing Success, we described the benefits of nutrition management in wine grapes using sap testing, also referred to as nutrient uptake testing.

Plant sap tests provide data on the total dissolved minerals immediately available to the plant and provide fast and accurate feedback on nutrient status.In addition to “real-time” detection of deficiencies, toxicities or imbalances, sap testing assists in identifying the most appropriate fertiliser applications.

Traditional dry matter testing analyses nutrients present in the leaf dry matter, which are minerals fixed in the organic plant material. These are mainly complexed in cell walls and not available for plant development.

Farmlands has seen an upsurge in Marlborough grape growers using sap testing, as they seek to better understand grapevine nutritional demands and  how to accurately manage plant nutrition. Sap testing is providing growers a better understanding of nutritional plant requirements during the growth stages of the vine. Growers can fine-tune and better manage nutrition and ultimately improve yields and quality. With increasing nutrition product prices, cost is more effectively managed using sap testing i.e. the ability to measure what is managed.


We no longer need to rely on historical laboratory data for nutrition status, when sap testing the plant can effectively tell us in real time what nutrients are required.

If you would like to discuss sap testing, please talk to your friendly Farmlands Technical Advisor.

Article provided by Mart Verstappen, Technical Leader – Viticulture, Farmlands Co-operative.